Page 922 - Basic Electrical Engineering

Figure 13.5 The interior of the earth showing source of geothermal energy

Geothermal power plants are built where geothermal reservoirs are
available within a depth of a few km from the earth’s surface. This requires

drilling into the earth to extract hot water and dry steam. California in USA
produces the most electricity from geothermal energy. Other uses of

geothermal energy is to use hot water from the reservoir or naturally available
hot springs for heating buildings, bathing, etc. In India, although electricity

generation from geothermal energy is at an initial stage, use is made of hot
springs for bathing as many believe that taking bath in mineral-rich natural
hot water will have a healing effect.

13.8 TRANSMISSION AND DISTRIBUTION OF ELECTRICITY
Electricity generated in power stations are brought to the consumer premises

through transmission and distribution systems. Power transmission is from
the substation near the power plant to the substation near the populated area

or industrial area. In substations, the voltage level of the power generated is
either stepped up or stepped down using step-up or step-down transformers.
Power is transmitted at high voltage using transmission lines. Fig. 13.6 shows

the schematic diagram of a power system.
The distribution system includes overhead lines and underground cables

drawn from the transformer substation and taken to the consumer premises,
i.e., to industries, commercial establishments, and residential areas.